Mechanism including an intermittently moved structure



June 3, 1941,

MECHANISM INCLUDING AN INTERMITTENTLY MOVED STRUCTU E. .J. KINGSBURY ETAL 2,244,453

Filed March 15, 1940 10 Sheets-Sheet l June E. J. KINGSBURY E A 2,244,463

MECHANISM INCLUDING AN INTERMITTENTLY MOVED STRUCTURE Filed March 15, 1940 10 Sheets-Sheet 2 "-mwua; Z;

Fume P E. J. KINGSBURY E I 2,244,463

MECHANISM INCLUDING AN INTERMITTENTLY MOVED STRUCTURE Filed March 15, 1940 10 Sheets-Sheet 3 June E. J. KHNGSBURY ET 2,244,453

MECHANISM INCLUDING AN INTERMITTENTLY MOVED STRUCTURE Filed March 15, 1940 10 Sheets-Sheet 4- m/WC. B M ifm Jun a. 1941. Y m. KINGSBURY HAL 2 244 463 MECHANISM INCLUDING AN INTERMITTENTLY MO VED STRUCTURE Filed March 15, 1940 10 Sheets-Sheet 6 June 3, 1941.. J KINGSBURY EI-AL 2,244,463

MECHANISM INCLUDING AN INTERMITTENTLY MOVED STRUCTURE Fiied March 15, 1940 10 Sheets-Sheet 7 June 4 E. J. KINGSBURY ETAL I 2,244,463

MECHANISM INCLUDING AN INTERMITTENTLY MOVED STRUCTURE Filed March 15, 1940 7 l0 Sheets-Sheet 8 JOJ 95 6 6 4 j HH .IK] I H 0 J0] g (919'- c T 1 g a? 6 r V: Q/ 9 i, 9) (9 I fig Q J a g y I 629 I x. J 9a 8% a4 I] I! ('99 H r, 7 J2 i 2 f [I r 93 w i a9 J r J) l 4 7 g [mgr/7&5

I MM E. J. KINGSBURY ETA-l. MEGHANI'SM INCLUDING AN INTERMITTENTLY MOVED STRUCTU June 3, 1941.

Filed March 15, 1940 10 Sheets-Sheet 9' June 3, 1941. E. J. KINGSBURY EI'AL.

MECHANISM INCLUDING AN INTERMITTENTLY MOVED STRUCTU 10 Sheets-Sheet l0 Filed March 15, 1940 Patented June 3, 1941 UNITE.

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MECHANISM: INCLUDING AN INTER- MITTENTLY P/IGVED STRUCTURE tion, Keene, N. H.

Hampshire Application March 15, 1940, Serial No. 324310 (CL Vii-43) 19 Claims.

This invention relates to improvements in systems including structures which are to be intermittently moved between accurately determined positions.

One of the features of the present invention is the provision of mechanical elements including a reversible source of power which upon operation in one direction produce a harmonic motion of the structure through greater than a finally-desired distance, in association with means for effooting a reversal of the source of power and thereby producing a retrograde movement of the structure to the desired position.

Another feature of the invention is the provision of mechanical elements including a reversible source of power, together with a clutch and worm wheel drive for moving the structure, and control means by which the source of power operates in one direction with a positive engagemcnt of the clutch for moving these elements and producing a movement of greater than a finallyrequired amount, followed by a reversal of the source of power and a retrograde operation through the worm wheel and worm so that the engagement of a structure with a stop produces a reaction between the worm wheel and worm which eiiects a relative opening of the clutch.

A further feature of the invention is the provision of elements including a reversible source of power, a clutch, a worm assembly including a spring for normally closing the clutch, a worm Wheel engaged with the worm, and means for moving the structure from the worm wheel, wherewith a movement of the source of power in one direction causes the structure to turn through a distance greater than that finally desired, together with control means for reversing the source of power so that the structure is given a retrograde movement until engaged with a stop and thereafter reaction between the worm and worm wheel causes the clutch to open against the action of the spring and the spring is effective for holding the structure engaged with said stop.

A further feature of the invention is the provision of mechanical elements and electrical structures by which a reversible electric motor is caused to effect a forward movement of the structure through more than the finally-desired distance, and thereupon mechanical control of the electrical system causes a reversal of the motor and a retrograde movement of the structure until it engages a stop, together with direction-controlled switch means for determining the operation of the electrical system.

A further feature of the invention is the provision of reversible mechanical means for operating a structure, and including a revoluble body carrying a crank shaft which is rotated during the revolution of the body and effectively presents its crank pin for operation. of an intermediate member whereby to produce a harmonically accelerated and decelerated movement of thisintermediate member and thereby produce a corresponding harmonic motion of the structure to be moved.

Another feature of the present invention is the provision of means for accurately positioning and guiding a revoluble structure and permitting. the take-up of looseness in parts and a centralizing of the path of movement thereof.

A further feature of the present invention is the provision of means for accomplishing the movement of an intermittently-driven member from one position to another accurately, and through the employment of elements effective for reducing the necessary power during a major part of each movement and for assuring definite positioning of the member in its final position.

With these and other features as objects in view, an illustrative form of practicing the invention is set out on the accompanying drawings in which:

Figure 1 is a side elevation of a machine embodying the present invention, with parts eliminated for better showing the general construction of the apparatus.

Figure 2 is a diagrammatic view, corresponding to a top view of Fig. 1, and indicating the successive individual turrets and stations.

Figure 3 is an upright fragmentary sectional View, on a larger scale than that of Figs. 1 and 2, substantially through the axis of the turret.

Figure dis a horizontal sectional view substantially on line 4- of Fig. 3.

Figure 5 is a horizontal sectional View, substantially on line 5-5 of Fig. 6, showing the mounting of the guiding rollers.

Figure 6 is a sectional view of the mounting for the guiding rollers.

Figure 7 is a sectional view substantially on line i--l of Fig. 9 showing a turret locating pin with its associated parts.

Figure 8 is a fragmentary view, on a portion of the bottom of the turret, showing a set of locating plates.

Figure 9 is a sectional view substantially on line 99 of Fig. 8.

Figure 10 is a sectional view through the driving assembly, substantially on lines Iii-Ii! of Figs. 3 and 11,

Figure 11 is a sectional view through the driving assembly, substantially on lines lI-l! of Figs. 4 and 10.

Figure 12 is a sectional view substantially on line 12-42 of Fig. 11.

Figure 13 is a sectional view substantially on line lS-I3 of Fig. 11.

Figure 14 is a circuit diagram.

An illustrative application of the present invention to a machine tool comprising a turret rotatable about a central vertical column of a machine base, and employing a plurality of individual machine units, is shown in these drawings. The general machine base B is provided with a turret table T which receives a predetermined number of Vises or like fixtures F which are secured to the table and are carried in rtation therewith about the central column provided by the machine. This central column includes an upstanding member M which, in the illustrative form, has a radial flange Ma at its lower end for engaging the base B and having a top surface for supporting the turret table T. Above the member M is a structure N for supporting certain of the machine units, and including a hollow cap member C within which is rotatalbly mounted a central spindle S.

In the illustrative form of Figs. 1 and 2, the turret table T is provided with twelve equidistant Vises or fixtures F: and the machine base is illustrated as provided with eleven machining units Pl, P2, P3 PH. The specific construction and arrangement of these individual units, and their particular mounting with respect to the base and turret, depends upon the article which is to be fabricated while supported in a fixture F. Illustrative mounting and employment of such units are shown in Figs. 1 and 2, and correspond generally to the arrangements set out in the Kingsbury and Swahnberg Patent 2,011,487 and the Swahnberg Patent 2,011,488. In the illustrative showing herein, certain of these units are positioned on the member N with their tool axes vertically above the corresponding stations, while two of the units are located a on angle brackets supported on the base member B. It will be understood that these tool units are interchangeable, and can be positioned and adjusted as required for the article to be made, and are fitted with the requisite drills, reamers, taps, etc., for performing the operation. These units are thus provided with the tools, and are individually adjusted for operation at their maximum efficiency. Thus, one unit may perform a rough drilling operation, a second unit will perform a finish-boring operation, and a third unit a tapping operation upon the article as it successively moves from stationto station in the intermittent movement of the turret table.

Each of the machining units or tool heads Pl, P2, P3 is illustratively provided with a head driving motor HMI,HM2,HM3 for causing the individual unit toperform its cycle. At the start and lClOSB of each cycle, the individual switch HS-l, HS2, HS-3 of the unit is in closed position. Each unit further has a detaining means which stops it at the close of its cycle, and may be released upon energization of the individual trip coil HT-|, HT2, HT-3 The driving system of the present invention is here illustrated as employed for accomplishing the intermittent movement of the table T. The structure includes a platform which is provided with a nut 2i engaged with a thread iii 22 on the lower end of the spindle S. This platform may thus be raised and lowered by rotating the spindle S by employment of a wrench or other suitable tool on the squared upper end thereof. When the platform 23 has been lowered to its bottom position, it rests upon rolls 23 carried !by the plate Ba. The inner end of the platform 2'0 has the fingers 24 which engage a guide post 25 and prevent rotation of the platform about the axis of the spindle S. It will be noted that the spindle S passes through and is guided by the upstanding reinforcing web structure 26 of the platform 20. When the platform 28 is lowered (dotted lines Figure 3) onto the rollers 23, the spindle S may be drawn out of the top of the machine, and then the platform, with the turret-driving structure, may be rolled through a front door of the base B. When the platform 2!] and the driving structure have been raised into the operating position, the spindle may be clamped against accidental rotation by a strap 27 having a pin 28 which engages in an aperture in the base of the platform 20. The spindle S is supported by an anti-friction bearing 29 carried in part :by the member M; the downward thrust of the spindle S is transmitted through the dowel pin 30 to the sleeve 3| and thus to the inner member of the antifriction bearing 29 The lower end Sa of the spindle S is guided in a suitable aperture of the base plate Ba.

The outer Wall of the member M has a flange 35 which supports a hardened ring 36 with a truly concentric external surface. This ring 36 is held by the locating pin 31 and by the cap screws 38.

The turret table T rests upon the general machine structure, and is provided with a plurality of guiding rollers 46 which engage with the peripheral face of the hardened ring 36. Each of .these rollers is carried by a bushing 4| mounted on an eccentric portion 42 of a pivot pin 43 which has an enlarged downwardly-divergent conical upper end. This upper end also has a hexagonal recess 153a for engagement by a proper wrench for turning the pivot pin and thereby adjusting the corresponding roller 40. A plate id has a conical aperture to fit the upper end of the pivot pin and is held in position and against rotation by means of screws 45a; and screws 45 may be tightened, after an adjustment of th roll G0 tohold the pivot pin against displacement, by clamping the plate 44 and ring 44a together, so that ring 4 3a. presses against the enlarged end of pivot pin 43.

An internally-cut gear ring 5! is secured to the underface of the turret table T by bolts 5|, and is utilized in producing the desired movement of the turret table.

The drive for the turret table is accomplished from motor mechanism supported on the platform 26, and in the illustrative form, two units TM are provided in order to equalize the pressure effects, although it is obvious that one or more units may be employed in accordance with the requirements of the particular machine. As these units are essentially identical in construction, a description of one of them will serve for both. The position of each such unit upon a the platform 29 is adjusted and determined in accordance with the relative diameters of the gear ring 50 and the driving pinion I to assure proper meshing, the size of the pinion I being selected as a fraction of the size of ring 52 corresponding to the number of stations operations. In this illustrative form, as set out in the aforesaid patents, each of the machining units PI, P2, P3, etc, is provided with a switch HSI, HS2, HS3 which is open during the normal course of operation of the unit, but is closed upon the return of the parts of the unit to a withdrawn position at which there is no interference between the unit tool (such as a drill, reamer, etc.) and the indexing movement of the turret with the fixtures and articles thereon.

A manner of connecting the electrical elements, with conventionalized showing of relays employed, is set forth in Fig. 14. In this figure, the apparatus is assumed to be supplied with three-phase alternating current when the main switch SW is closed. Current then flows through the phase conductors I45, III and I42 and the branch conductors I43 to the forward relayFR and the reverse relay RR and thence in accordance with the selective energization of these relays to the indexing motor IM, and also flows through the branch conductors I 34 for energizing the motors HMI, HM-2, HM3 of the individual work units.

In this circuit diagram, it will be assumed that a lower position of a switch is the normal one, and that the switch contacts of a relay are raised upon energization of the relay, and that the single circuit switches AIS, MIS, HS-I, I-IS2 are normally in the lower and open position.

The control circuits are supplied by a conductor I50 which is branched from phase conductor I40 and may include a fuse II. This conductor I50 connects the several switches HSI, HS2, HS3 of the several working units in series, these switches being so constructed and arranged in the particular unit that they are individually closed when the individual unit has performed its cycle and returned to a rest position in which the turret may be indexed. Such arrangements of parts are described in the Kingsbury et al. Patent 2,011,487 and the Swahnberg Patent 2,- 011,488. From the last of these head switches, this series circuit continues by a conductor I52 to the automatic indexing switch AIS and the hand indexing switch MIS which are connected in parallel, and also to a lower contactor of the jog switch JS. This jog switch JS is shown as a two-pole switch that, when closed, permits completion of holding circuits for assuring completion of cycles of automatic operation and, when open, permits jogging, e. g. movements of distance and duration controlled manually by closing and opening of the manual indexing switch MISL When either the automatic or the manual indexing switch is closed, current flows to the conductor I53 and to the normally-closed contacts of a control relay CR-Z and thence by conductor I54 to the coil of a control relay (JR-I with a return by conductor I55 to phase conductor I42. Control relay CRI is thus energized and closes.

When the relay CR--I closes, current can flow from conductor I52, through the lower contacts and. blade of the jog switch JS to con-ductor I56, through now-closed contacts of relay CR-I to conductor I53; this holding circuit through the switch JS shunts the indexing switches AIS and MIS, so that these switches may now be opened without disturbing the energization of the coil of relay CR-I.

Further, the closing of relay CRI establishes a circuit from conductor I5II through the overload circuit-breaker I57, conductor I58, nowclosed contacts of relay CR-I, conductor I59, to the coil of the forward relay FR. The forward relay FR closes and the indexing motor IM begins to move in a forward direction.

After a short time interval, the beveled surface II5 engages the lock pin I25 and depresses the same and thereby moves the lock pin switch LPS into its lower position. A circuit is now established from conductor I50 through the overload circuit breaker I51 and by conductor I58 to an upper contact of the jog switch JS. This jog switch JS closes a continuance of this new circuit by conductor I50 to lock pin switch LPS and through the lower closed contact thereof to conductor I5I, through a normally closed contact in relay CR2, conductor I52, the coil of relay CR2 to conductor I55 and thus back to phase conductor I42. Control relay CR--2 is energized and closes.

The closing of control relay CR2 establishes contacts which connect conductor I 55 to conductor I 82 to establish a holding circuit for relay CR2 under control of the lower contacts of jog switch JS. The coil of the closed relay CR-I has been supplied through normally closed contactors of relay CR2 which have connected conductors I53 and I54; but now the closing of relay CRI2 opens the circuit by conductors I53, I 54 and relay CRI is de-energized. At the same time, however, a circuit is established from conductor I6I by now-closed contacts of relay CR-Z direct to conductor I59, so that the forward relay FR. remains energized and the indexing motor IM continues to turn forwardly under control of the jog switch JS and the lock pin switch LPS.

When the turret has reached the new station in the course of the indexing movement, the lock pin I20 snaps into the corresponding recess III} and the lock pin switch LPS opens the contact to conductor IfiI and again closes a contact to conductor I63. By opening the circuit through conductor I5I, the current flowing through the coil of forward relay FR ceases and the indexing motor IM is deenergized. The closure of contact at lock pin switch LPS to conductor I53 establishes a circuit from conductor I55 through conductor I53, the upper contacts of jog switch JS, conductor I55], switch LPS, conductor I53, normally-closed contacts of relay CRI for conductor I55, the coil of reverse relay RR, to conductor I55 and back to phase conductor M2. The reverse relay RR is energized and closes, and current now flows to the indexing motor IM with phase reversal so that this motor is plugged and then reversed in direction of movement.

The closing of relay RR also closes control contacts by which conductor I58 is connected to conductor I65 and thence through a nowclosed contact of relay CR-2, by conductor I56 to the coil of the head tripping relay HTR, with a return by conductor I57 to conductor I55 and thus to the phase conductor I52. The energization of relay HTR closes circuits from the phase conductors I 40, I iI, I 42 to the head tripping conductors I10, and the tripping coils HT-I, I-IT--2, HT-S of the individual heads are energized. It will be noted that these tripping coils are connected in delta for each three working units and thus the loading of the three-phase line is substantially balanced, which is an extremely desirable condition when a great number of heads are employed. The effect of energizing the coils HT-I, HT-Z, HT-3 is to release the detaining means which previously have been holding the working units against starting a cycle. Therefore, the individual units are now operated for initiating their individual cycles.

Meanwhile, the retrograde movement of the indexing motor IM has caused the upright face I I6 of the corresponding recess lid of the turret tabl to be brought against the upright face l2! of the lock pin I26, so that the turret is brought accurately to the station and is maintained thereat.

As the work units, begin to operate, their individual switches HS-l, I-IS-Z, PIS-3 are opened. The opening of any one of these switches breaks the circuit through conductors H58, I52 to the lower contacts of the jog switch JS and through conductors 455, I53, I54 and relay Cit-2 drops to the normally open position.

The individual work units now perform their functions in individual cyclic fashion and withdraw until all of the head switches I-IS-i, I-lS-2, HS-3 are closed. The series circuit through conductors I56, I52 is now reestablished, and a further manual indexing can be accomplished by closing the hand indexing switch MIS.

To describe a cycle of operation of the structure,

it will be assumed that all of the working heads or units Pi, P2, P3 have individually completed their cycles and have returned to the withdrawn position in which their corresponding individual switches PIS-4, IiS-2, HS-3 are closed, and in which the individual units are ready for a further performance of their cycles upon energization of the individual trip coils HT-i, TIT-d. HT-S The automatic indexing switch AIS is assumed to be open, so that the apparatus will perform on a semi-automatic basis; that is, upon a single manual manipulation, an indexing is accomplished and each of the working units or heads Pl, P2, P3 performs a single cycle of operation, and then all parts return toa position at which a further indexing and working can be effected by a second manual operation, etc. The manual indexing switch MIS is normally open. The jog switch JS is in closed position. The lock pin switch LPS is in raised position, as the lock pin P25 is in its uppermost position in a recess i if].

Upon manual operation of the switch MIS, a circuit is established by which relay CR-l is energized, and this in turn closes the forward relay FR, and the indexing motor 1M is energized for forward movement. The rotation of motor IM causes revolution of its shaft 6i and of the worm 88 in the direction shown by the arrows, and the Worm drives the worm wheel 8!] so that the reaction thrust is toward the right in Fig. 10 and the clutch 67 is held closed so that essentially a positive drive is effected, and the main rotating body 83. turns in the direction of the arr-ow (Fig. 11) carrying the crank shafts 85 with it. The gears 83 roll on the stationary gear 89 and the crank shafts 85 are thus rotated so that their cranks '3'! press the blocks H]! against the walls of the grooves Hit of the disk 98 and the latter is driven by a harmonic motion so that there is an acceleration to a maximum speed (when the blocks iii! are substantially at the outer ends of the grooves li fl in the illustrated form), and therewith the driving head 96 is driven and carries the central shaft ea, 95 in rotation with it and the pinion H drives the gear ring 5i! secured to the turret table. In this way, a harmonic motion of the turret table is produced with acceleration and deceleration. The parts are so constructed and arranged that the turret table is thus driven through a slightly greater angle than that corresponding to the angular spacing of the stations at which the turret is to be brought to a standstill.

Shortly after the turret begins to move, the lock pin iii! is depressed and the switch LPS is moved downward. A circuit is established through conductor E59, switch LPS, conductor ltl, normally closed contacts of relay CRr-2, conductor 362, and the coil of the holding relay GEL-2 is closed. Relay Cit-i now sets up its own holding circuit from conductor its to conductor I62, and likewise establishes a circuit fromv conductors Hi! to see to maintain energization of the forward relay FR.

As the turret passes the position at which it is to be held at a standstill, the lock pin i2!) is pressed upward by its spring I25 and engages in the recess HG corresponding to this new station. This upward movement of the lock pin I20 produces a shifting of the lock pin switch LPS, so that the circuits are now re-established to terminate energization of the forward relay FR through conductor ldl and to energize the reverse relay RR and the motor is plugged to a standstill and then caused to turn in a retrograde direction. At this time, the worm E8 is rotated opposite to the direction of the arrow, and the reaction of the worm in the worm wheel causes the worm to move relatively toward the left (Fig. 10) when resistance is encountered, against the action of spring '12. Such resistance occurs when the upright face l2! of the lock pin Q26 engages the upright face H5 of the block H2, during the retrograde movement of the turret. This leftward shifting of the worm 68 and its shaft operates to disengage the clutch 6'! so that the indexing motor IM may continue to turn without driving the system.

During the course of the retrograde movement of the turret, contacts of the relay RR serve to energize the conductors W5, H56 so that the trip coils HTi, HT--2, HT-fi are energized and effect an initiation of the operation of the individual working units or heads Pi, P2, P3 It will be understood that these units are so constructed and arranged that a forward traverse occurs before the tools come into the paths of any parts of the turret, fixtures or article of work, so that the short retrograde movement of the turret table causes no difficulty.

During the course of the operation of the worklog units or heads Pl; P2, P3 the spring l2 presses the worm (53 against the worm wheel 83, and acts through the system to prevent any looseness or back-lash, and holds the turret under resilient pressure ina retrograde direction so that the block H2 remains pressed tightly against the lock pin i.

As each work unit completes its cycle and returns to and is detained in its withdrawn position, the corresponding switch IIS, HS2, is closed. Ultimately, the system is restored toits forward condition, and a further cycle can now be initiated by again closing the manual indexing switch MIS.

If it is desired to have a completely automatic operation, in which indexing movements automatically alternate with the performance of individual cycles of completed movements by the working units or heads Pi, P2, P3 the automatic indexing switch AIS is closed and remains closed. As this switch AIS is in multiple with the manual switch MIS, the completion of a working cycle by the last of the working units or heads Pl, P2, P3 will result in the closure in the last of the switches HS-I, I-IS-Z, HS3 and current will now flow through conductors E50, I52 and switch AIS and provoke directly a further'indexing movement.

During the initial adjustment of the structures, and at other times, it is desirable to be able to cause the turret to move forward by a jogging or inching movement under strict control of the operator. This can be effected by opening the jog switch JS. Upon then closing the manual indexing switch MIS, current can flow from conductor I52 to conductor l53, through normally closed contacts of relay CR-Z, conductor I54 and energize the coil of relay CRI; this relay CR.l closes, and for ward relay FR is closed and the index motor IM can turn forwardly so long as the switch MIS is held closed. Upon releasing this switch, the relay CR.| opens and therewith the forward relay FT and the system comes to a standstill again; it will be noted that the opening of the jog switch JS does not permit closing of the holding circuit through the relay CRI, as the path between conductors I52 and I56 is interrupted. Further, the jog switch JS opens the path between conductors I58 and I60, so that the lock pin switch LPS remains de-energized, and no current can flow through the coils of the relay CR,2 or the reverse relay RR; hence, the turret does not perform its succession of forward and retrograde movement under control of the lock pin switch LPS; nor are the work units released, as the circuit through conductors I35, I 66 is interrupted both at the relay CR-2 and at the reverse relay RR.

As shown in Figures 3, 6, 7 and 10, it is preferred to form the driving pinion I65 and the ring 50 with skew gear teeth. The angle and direction of the teeth are so devised that the reaction between the teeth is effective during the forward movement of the turret driving unit TM for producing an upward component of motion of this table, so that the pressure between the bearing surfaces H1, H8 is relieved in part and a rapid and free indexing movement of the table or dial T can be accomplished. This arrangement of skew teeth is further effective upon reversal of the indexing unit TM to produce a downward component of the movement upon the table T, which produces forces at the surfaces H1, H8 tending to act as a brake during the short retrograde movement; and also serving to pull the table down for accurate registration at the time it is brought to a standstill in its'retrograde movement by the action of the lock pin I20. It will be noted that the lifting forces developed during the forward movement are transmitted to the platform 20 and thus essentially balance themselves as the units must obviously have like arrangement of parts; while the downward forces during retrograde movemetn are accomplished by the abutting engagement of parts of the unit with the flange Ma closely adjacent to the point at which the downward pressure itself is being exerted, so that there is little strain upon the table T or the flange Ma tending to warp either of them from their true positions.

It will be noted from Figs. 3, and 6- that the turret table T is not journaled and guided concentrically in a direct manner by the central element M, but rests upon ways provided by the upper surface of the flange Ma. The hardened steel ring 36 is secured to the central structure M in concentricity with the general axis. The axis of the turret table is determined by the positions given the several rollers 49, and these rollers can be adjusted and secured to obtain and maintain a desired relative radial position for the several fixtures. If looseness develops, or it is otherwise desired to adjust the parts, this is effected by releasing the central or hold-down lock screws t5 (Fig. 5), so that the plate and ring Ma are loosened. A suitable wrench is then inserted in the hexagonal recess 43a of the roller pivot pin 43 and the latter is turned so that its eccentric portion 42 causes the roller 40 to move toward or away from the common axis. When proper adjustments have been effected, the binding engagement between the plate 4 3 and the upper conical end of pin 43 is again effected, by tightening the screws 45 which tend to relatively raise the clamping ring 44a. It will be noted that the entire assembly can be withdrawn by releasing the hold-down screws 4511.

It is obvious that the invention is not limited to the illustrative form shown and described, but may be practiced in many ways within the scope of the appended claims.

We claim:

1. In a driving system for a turret or like structure which is to be moved successively through predetermined intervals, a reversible source of power, means driven from the source of power to actuate the structure, a stop member for limiting retrograde movement of the structure upon reversal of the source of power, a slip clutch included in said driving means for disconnecting the source of power from driving relationship with the structure when the latter is engaged with the stop member, means elfective for re-engaging said clutch and for holding the structure against said stop member, means for initiating forward movement of the source of power, and means for effecting reversal of movement of said source of power after a predetermined relative forward movement of said structure.

2. A system as in claim 1, in which the initiating means includes an initiating switch, and the initiating and reversing means include control relays and circuits controlled thereby for causing the source of power to be energized for automatically completing a cycle of movement, and also including a jog switch and circuits connected therewith for establishing selective holding circuits for said relays in one position of the jog switch for assuring the completion of the cycle, said jog switch and its said associated circuits being effective in another position of the jog switch for preventing establishment of the holding circuits and assuring a continued forward movement of the source of movement under control of the initiating switch.

3. In a driving system for a turret or like structure which is to be moved successively through predetermined intervals, comprising a reversible source of power, a worm driven by said source of power, a worm wheel in mesh with the worm, means actuated by the worm wheel for moving said structure, a spring elfective for moving the worm axially for thereby producing a retrograde movement of the wheel, a slip clutch included between said source of power and said worm and normally held engaged by said spring,

a stop for limiting the retrograde movement of the structure, means for initiating forward movement of the source of power, and means for effecting reversal of the source of power upon a predetermined forward movement of the structure.

4. A system as in claim 3, in which the reversing means includes a switch, and said stop is constructed and arranged to move upon a predetermined forward movement of the structure, said stop including means for actuating said switch.

5. A turret mechanism including a turret, a gear on the turret, a driving pinion in mesh with the gear, a revoluble member connected for rotating the pinion, said revoluble member having at least one substantially radial groove therein, a source of power, a revoluble body carrying a crank shaft eccentric to its own axis, a crank pin on said shaft engaged in said groove, a first gear on said crank shaft, and a fixed gear in mesh with said first gear, said revoluble body and fixed gear being effective to cause a rotation of the crank shaft about its own axis during the revolution of said body and to cause said crank pin to move in said radial groove and thereby produce a harmonic accelerating and decelerating movement of said rotatable member and of said turret.

6. A turret mechanism including a turret, a gear on the turret, a driving pinion in mesh with the gear, a revoluble member connected for rotating the pinion, said revoluble member having at least one substantially radial groove therein, a source of power, a revoluble body carrying a crank shaft eccentric to its own axis, a crank pin on said shaft engaged in said groove, said body being concentric with said member, a first gear on said crank shaft, and a fixed gear in mesh with said first gear, said revoluble body and fixe gear being effective to cause a rotation of the crank shaft about its own axis during the revolution of said body and to cause said crank pinto move in said radial groove and thereby produce a harmonic accelerating and decelerating movement of said rotatable member and of said turret.

'7. In a turret mechanism, a reversible electric motor and means driven thereby for moving the turret in either direction, forward and reverse switching means for the motor, initiating relay, a holding relay, circuit means including contacts of the initiating relay for energizing said switching means to produce forwardrnovement of the motor and turret, means responsive to the turret movement and to the position of the initiating relay for energizing the holding relay,

circuit means including contacts of said holding relay for de-energizing the initiating relay and for maintaining energization of the switching means when the holding relay is closed, a jog switch, and circuit means including said jog switch and said responsive means for further energizing the switching means in one position of the jog switch and thereby producing a reversal of the motor and retrograde movement of the turret following a predetermined forward movement.

8. A turret mechanism comprising a reversible electric motor, a clutch driven from the motor, a worm driven from the clutch, and a spring effective upon the worm to move, the same axially and thereby hold the clutch engaged, a Worm wheel in mesh with the worm, means driven by the worm wheel for turning the turret, means for reversing the motor, a stop for limiting retrograde movement of the turret; the worm, worm wheel, clutch and spring being so constructed and arranged that the clutch engages during rotation of the motor for producing forward movement, and the worm threads in the worm wheel when the turret is detained by the stop and thereby moves axially against the spring for opening the clutch, said spring being then effective for pressing the worm axially during its engagement with the worm wheel and thereby holding the turret against said stop.

9. A turret mechanism including a turret to intermittently moved through a predetermined distance, a reversible source of power, an axially movable member driven by said source and having a worm thereon, a spring for moving the member axially, a stop to limit retrograde movement of the turret, a worm Wheel in mesh with the Worm, means driven by the worm wheel for moving the turret, and means for energizing the source of power including elements for producing a forward movement thereof whereby the turret is moved past the finally-desired position, and elements effective after said forward movement for causing the source of power to be reversely energized for retrograde movement of the turret until the latter engages the stop whereby the worm wheel is brought to a standstill, the worm thereupon threading in the worm wheel and moving axially against the action of the spring, said spring being thereby eiTective through the worm and worm wheel for holding the turret engaged with the stop.

10. A. turret mechanism comprising a base member and a revoluble turret member, one of said members having a circular guide ring, the other said member having a plurality of guiding members; each said guiding member including a roller engaged with the guide ring, and pivot means for said roller, said pivot means including an eccentric portion so that a rotation of the pivot means Will cause movement of the roller toward and from the axis of the guide ring, and means for holding the pivot means against rotation.

11. A turret mechanism comprising a base having a peripheral flange and an upstanding central structure projecting above the flange, said central structure including a circular guide ring, a revoluble turret resting upon the flange, and a plurality of guiding members mounted on the turret and disposed about said central up" standing structure; each said member comprising a roller engageable with the guide ring for guiding the turret in its revolution, a pivot pin rotatable in a bearing on the turret and providing a bearing for the roller, oneof said bearings being eccentric to the other whereby a rotation of the pivot pin will produce movement of the roller toward and from the axis of the guide ring, and means connected to the turret for holding said pivot pin against rotation.

12. A turret mechanism comprising a base having a peripheral flange and a central upstanding structure projecting beyond the flange, a circular ring secured to said upstanding structure above the flange, a revoluble annular turret resting upon the flange, and a plurality of guiding members mounted on the turret and disposed about the inner periphery of the same; each said member comprising a roller engageable with the hardened ring for guiding the turret in its rotation, a pivot pin having a bearing in said turret to determine its axis of rotation and also providing a bearing for the roller, said roller bearing being eccentric to the pivot axis whereby rotation of the pivot pin will produce movement of the roller toward and from the central axis, said pivot pin also having a conical portion concentric with its axis, a clamping member having a conical socket for receiving said conical portion and secured to the turret, and a clamping plate engageable with said pin for pressing the conical portion into said socket whereby to prevent rotation of the pin about its axis, and. means for pressing said plate against the pin.

13. A turret mechanism comprising a hollow base'and an annular turret structure rotatable about a vertical axis relative to said base, indexing means for intermittently movim the turret structure including a source of power and devices driven thereby for moving said structure, a platform in the hollow base and having parts of the said devices secured thereto, and threaded means engaged with the platform for raising and lowering the same and including a spindle extending upwardly through the turret structure and accessible above the same.

14. A turret mechanism as in claim 13, in which the threaded means may be separated from the platform upon actuation of the spindle,

and including locating means in the base for determining a position of the platform in which the threaded means may be engaged therewith and from which it may be raised for presenting the said parts in position for moving the turret structure.

15. In a turret mechanism, a base, a turret rotatable relative to said base, a bearing between said turret and base, power driven means for rotating the turret in either direction and including a skew-driving pinion and a meshing skew gear on the turret, and selecting means for controlling the turret rotating means whereby to effect a long forward movement of extent greater than a predetermined indexing movement and thereafter by reversal of the rotation of said skew pinion to effect a short retrograde movement, said skew pinion and skew gear being effectiv by their reaction during the forward movement to effect a reduction of the pressure friction between the turret and the base and during the retrograde movement to increase said pressure friction.

16. In a turret mechanism, a base, a turret rotatable about a vertical axis, bearing means on the turret and base for supporting at least a part of the weight of the turret, power driven means for rotating the turret in either direction and including a skew driving pinion and a meshing skew gear on the turret, and selecting means for controlling the turret rotating means whereby to effect forward and retrograde movements thereof by reversing the direction of movement of the driving pinion, said skew pinion and skew gear being effective by their reaction during the forward movement to reduce the pressure of the turret at said bearing means. and during retrograde movement to increase said pressure.

17. In a driving system for a turret or like structure which is to be moved successively through predetermined intervals, a reversible source of power, means driven from the source of power to actuate the structure, stop means for limiting retrograde movement of the structure upon reversal of the source of power and including cooperating interengageable parts for limiting the retrograde movement, one of said parts being movable relative to the other for permitting movement in the forward direction, a slip clutch included in said driving means for releasing the source of power from driving relationship with the structure when the parts of said stop means are in effective engagement, means for initiating forward movement of the source of power, and means for controlling the forward and the reverse movement of said source of power including a control device actuated by said relative movement of said one part of the stop means for assuring the continued forward movement through a predetermined distance.

18. In a driving system for a turret or like structure which is to be moved successively through predetermined intervals, a reversible source of power, means driven from the source of power to actuate the structure, stop means for limiting retrograde movement of the structure upon reversal of the source of power and including cooperating interchangeable parts for limiting the retrograde movement, one of said parts being movable relative to the other for permitting movement in the forward direction, a slip clutch included in said driving means for releasing the source of power from driving relationship with the structure when the parts of said stop means are in effective engagement, means for initiating forward movement of the source of power, and means for controlling the continued forward and reverse movement of said source of power including a control device actuated by said relative movement of said one part of the stop means for controlling the direction of energization of said source of power.

19. A driving system for turret and like machines which include relatively fixed and movable structures, comprising a reversible source of power, means driven from the source of power to actuate the movable structure, stop means for limiting retrograde movement of the movable structure, including cooperating parts upon each of said structures, one of said parts having a stop element which is movable relative to the other said part in a direction at an angle to the direction of movement of the movable structure, at least one of said parts including surfaces for producing a said relative movement of said'element and for holding said element in its moved position during a predetermined travel of the movable structure, means included in said parts for returning said element from its moved position upon the completion of said predetermined travel, means for initiating forward movement of source of power, and means responsive to the position of said element for effecting the continued forward movement of said movable structure for said predetermined travel and for provoking a reverse movement thereof when said element is returned.

EDWARD JOSLIN KINGSBURY. GUNNAR SWAHNBERG. BENJAMIN NORTON FOSTER. 

